On Wed, Apr 8, 2020 at 7:13 PM Kito Cheng <kito.ch...@sifive.com> wrote:
>
> ping
>
> On Tue, Mar 31, 2020 at 4:33 PM Kito Cheng <kito.ch...@sifive.com> wrote:
> >
> > - The alignment for local variable was adjust during
> > estimate_stack_frame_size,
> > however it seems wrong spot to adjust that, expand phase will adjust that
> > but it little too late to some gimple optimization, which rely on certain
> > target hooks need to check alignment, forwprop is an example for
> > that, result of simplify_builtin_call rely on the alignment on some
> > target like ARM or RISC-V.
> >
> > - This patch fix gfortran.dg/pr45636.f90 for arm and riscv.
> >
> > - Regression test on riscv32/riscv64 and x86_64-linux-gnu, no new fail
> > introduced.
> >
> > gcc/ChangeLog
> >
> > PR target/90811
> > * Makefile.in (OBJS): Add tree-adjust-alignment.o.
> > * tree-adjust-alignment.cc (pass_data_adjust_alignment): New.
> > (pass_adjust_alignment): New.
> > (-pass_adjust_alignment::execute): New.
> > (make_pass_adjust_alignment): New.
> > * tree-pass.h (make_pass_adjust_alignment): New.
> > * passes.def: Add pass_adjust_alignment.
> > ---
> > gcc/Makefile.in | 1 +
> > gcc/passes.def | 1 +
> > gcc/tree-adjust-alignment.cc | 88 ++++++++++++++++++++++++++++++++++++
> > gcc/tree-pass.h | 1 +
> > 4 files changed, 91 insertions(+)
> > create mode 100644 gcc/tree-adjust-alignment.cc
> >
> > diff --git a/gcc/Makefile.in b/gcc/Makefile.in
> > index fa9923bb270..9b73288f776 100644
> > --- a/gcc/Makefile.in
> > +++ b/gcc/Makefile.in
> > @@ -1545,6 +1545,7 @@ OBJS = \
> > ubsan.o \
> > sanopt.o \
> > sancov.o \
> > + tree-adjust-alignment.o \
> > tree-call-cdce.o \
> > tree-cfg.o \
> > tree-cfgcleanup.o \
> > diff --git a/gcc/passes.def b/gcc/passes.def
> > index 2bf2cb78fc5..92cbe587a8a 100644
> > --- a/gcc/passes.def
> > +++ b/gcc/passes.def
> > @@ -183,6 +183,7 @@ along with GCC; see the file COPYING3. If not see
> > NEXT_PASS (pass_oacc_device_lower);
> > NEXT_PASS (pass_omp_device_lower);
> > NEXT_PASS (pass_omp_target_link);
> > + NEXT_PASS (pass_adjust_alignment);
> > NEXT_PASS (pass_all_optimizations);
> > PUSH_INSERT_PASSES_WITHIN (pass_all_optimizations)
> > NEXT_PASS (pass_remove_cgraph_callee_edges);
> > diff --git a/gcc/tree-adjust-alignment.cc b/gcc/tree-adjust-alignment.cc
> > new file mode 100644
> > index 00000000000..1269f93e56a
> > --- /dev/null
> > +++ b/gcc/tree-adjust-alignment.cc
> > @@ -0,0 +1,88 @@
> > +/* Adjust alignment for local variable.
> > + Copyright (C) 2003-2020 Free Software Foundation, Inc.
> > + Contributed by Dorit Naishlos <do...@il.ibm.com>
> > +
> > +This file is part of GCC.
> > +
> > +GCC is free software; you can redistribute it and/or modify it under
> > +the terms of the GNU General Public License as published by the Free
> > +Software Foundation; either version 3, or (at your option) any later
> > +version.
> > +
> > +GCC is distributed in the hope that it will be useful, but WITHOUT ANY
> > +WARRANTY; without even the implied warranty of MERCHANTABILITY or
> > +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
> > +for more details.
> > +
> > +You should have received a copy of the GNU General Public License
> > +along with GCC; see the file COPYING3. If not see
> > +<http://www.gnu.org/licenses/>. */
> > +
> > +#include "config.h"
> > +#include "system.h"
> > +#include "coretypes.h"
> > +#include "backend.h"
> > +#include "target.h"
> > +#include "tree.h"
> > +#include "gimple.h"
> > +#include "tree-pass.h"
> > +#include "cgraph.h"
> > +#include "fold-const.h"
> > +#include "gimple-iterator.h"
> > +#include "tree-cfg.h"
> > +#include "cfgloop.h"
> > +#include "tree-vectorizer.h"
> > +#include "tm_p.h"
> > +
> > +namespace {
> > +
> > +const pass_data pass_data_adjust_alignment =
> > +{
> > + GIMPLE_PASS, /* type */
> > + "adjust_alignment", /* name */
> > + OPTGROUP_NONE, /* optinfo_flags */
> > + TV_NONE, /* tv_id */
> > + 0, /* properties_required */
> > + 0, /* properties_provided */
> > + 0, /* properties_destroyed */
> > + 0, /* todo_flags_start */
> > + 0, /* todo_flags_finish */
> > +};
> > +
> > +class pass_adjust_alignment : public gimple_opt_pass
> > +{
> > +public:
> > + pass_adjust_alignment (gcc::context *ctxt)
> > + : gimple_opt_pass (pass_data_adjust_alignment, ctxt)
> > + {}
> > +
> > + virtual unsigned int execute (function *);
> > +
> > +}; // class pass_adjust_alignment
> > +
> > +} // anon namespace
> > +
> > +/* Entry point to adjust_alignment pass. */
> > +unsigned int
> > +pass_adjust_alignment::execute (function *fun) {
> > + size_t i;
> > + tree var;
> > + struct cgraph_node *node;
> > + unsigned int align;
> > +
> > + FOR_EACH_LOCAL_DECL (fun, i, var)
> > + {
Please skip vars with DECL_USER_ALIGN.
Note local-decls also contains the base variables that
are written into SSA form so you are processing variables
here that are not processed by the corresponding code
during RTL expansion. It's probably harmless to increase
alignment of registers since that should be ignored.
I'm not sure whether alignment has any effect on
DECL_HARD_REGISTER vars.
Note local-decls also contains local statics. I'm not sure
LOCAL_DECL_ALIGNMENT is supposed to handle those,
certainly the RTL expansion code does not. So please
exclude is_global_var (var) vars as well.
Thanks,
Richard.
> > + align = LOCAL_DECL_ALIGNMENT (var);
> > +
> > + gcc_assert (align >= DECL_ALIGN (var));
> > +
> > + SET_DECL_ALIGN (var, align);
> > + }
> > + return 0;
> > +}
> > +
> > +gimple_opt_pass *
> > +make_pass_adjust_alignment (gcc::context *ctxt)
> > +{
> > + return new pass_adjust_alignment (ctxt);
> > +}
> > diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
> > index a1207a20a3c..576b3f67434 100644
> > --- a/gcc/tree-pass.h
> > +++ b/gcc/tree-pass.h
> > @@ -480,6 +480,7 @@ extern gimple_opt_pass *make_pass_sprintf_length
> > (gcc::context *ctxt);
> > extern gimple_opt_pass *make_pass_walloca (gcc::context *ctxt);
> > extern gimple_opt_pass *make_pass_coroutine_lower_builtins (gcc::context
> > *ctxt);
> > extern gimple_opt_pass *make_pass_coroutine_early_expand_ifns
> > (gcc::context *ctxt);
> > +extern gimple_opt_pass *make_pass_adjust_alignment (gcc::context *ctxt);
> >
> > /* IPA Passes */
> > extern simple_ipa_opt_pass *make_pass_ipa_lower_emutls (gcc::context
> > *ctxt);
> > --
> > 2.25.2
> >
